Central Retinal Artery Occlusion as the Initial Manifestation of Occult Giant Cell Arteritis - A Diagnostic Enigma

Abstract

Giant cell arteritis (GCA) is a systemic vasculitis with a myriad of ocular manifestations such as Anterior Ischaemic Optic Neuropathy (AION), Central Retinal Artery Occlusion (CRAO), choroidal infarction, occipital lobe infarction and ocular motor nerve palsies. The predominant systemic features include fever, polymyalgia rheumatica, jaw claudication, weight loss and fatigue. Occult GCA accounts for a minority of cases presenting without systemic symptoms. It is a potential cause of bilateral blindness unless a high index of suspicion is contemplated. A 60 year old female presented with CRAO with no systemic symptoms of GCA. Cardiovascular examination, electrocardiography, echocardiography and carotid doppler were unremarkable. Erythrocyte Sedimentation Rate (ESR), C Reactive Protein (CRP) and platelets were normal. Bilateral prominent temporal arteries were noted but were non tender with subtle pulsations, leading to a suspicion of GCA. Temporal artery biopsy disclosed transmural granulomatous inflammation and fragmentation of internal elastic lamina, ascertaining the diagnosis. Systemic steroids were administered promptly. Although an unusual etiology of CRAO, GCA must be ruled out with utmost priority in patients older than 50 years. The diagnosis can be elusive in occult GCA and CRAO may be the inceptive manifestation, further compounding the diagnostic enigma. Urgent temporal artery biopsy is warranted in occult cases of GCA and substantiates the diagnosis in dubious cases. Occult GCA constitutes an ophthalmic emergency and the imperativeness of urgent systemic steroid therapy to prevent visual loss in the other eye cannot be overemphasized.